The best of these is Chromatic Lantern, which has the added ability to allow your lands to tap for any color of mana while also tapping for one itself all for three colorless mana
The restriction to the colorless identity is significant and made up for by rampant mana rocks that make high-cost spells easy to achieve
Ending up down three mana on a discard spell to make the trade isnt ideal, but its probably better than any other trade for Esikas Chariot and about the expectation of losing mana against Goldspan Dragon
If theres a solid two drop, like a 1/3 that Scries when you flash in your Gull, then getting extra value off of Vexing Gull is easy
Its a very narrow counter ability since it only gets loyalty abilities from planeswalkers, and is best when you stop a planeswalkers minus ability from sweeping the board in some cases (Elspeth, Sun's Champion comes to mind), but at least they lose the loyalty counters as the cost to activate that ability